1 //===--- TokenLexer.cpp - Lex from a token stream -------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the TokenLexer interface.
12 //===----------------------------------------------------------------------===//
14 #include "MacroArgs.h"
15 #include "clang/Lex/MacroInfo.h"
16 #include "clang/Lex/Preprocessor.h"
17 #include "clang/Lex/LexDiagnostic.h"
21 using namespace clang;
23 /// MacroArgs ctor function - This destroys the vector passed in.
24 MacroArgs *MacroArgs::create(const MacroInfo *MI,
25 llvm::ArrayRef<Token> UnexpArgTokens,
26 bool VarargsElided, Preprocessor &PP) {
27 assert(MI->isFunctionLike() &&
28 "Can't have args for an object-like macro!");
29 MacroArgs **ResultEnt = 0;
30 unsigned ClosestMatch = ~0U;
32 // See if we have an entry with a big enough argument list to reuse on the
33 // free list. If so, reuse it.
34 for (MacroArgs **Entry = &PP.MacroArgCache; *Entry;
35 Entry = &(*Entry)->ArgCache)
36 if ((*Entry)->NumUnexpArgTokens >= UnexpArgTokens.size() &&
37 (*Entry)->NumUnexpArgTokens < ClosestMatch) {
40 // If we have an exact match, use it.
41 if ((*Entry)->NumUnexpArgTokens == UnexpArgTokens.size())
43 // Otherwise, use the best fit.
44 ClosestMatch = (*Entry)->NumUnexpArgTokens;
49 // Allocate memory for a MacroArgs object with the lexer tokens at the end.
50 Result = (MacroArgs*)malloc(sizeof(MacroArgs) +
51 UnexpArgTokens.size() * sizeof(Token));
52 // Construct the MacroArgs object.
53 new (Result) MacroArgs(UnexpArgTokens.size(), VarargsElided);
56 // Unlink this node from the preprocessors singly linked list.
57 *ResultEnt = Result->ArgCache;
58 Result->NumUnexpArgTokens = UnexpArgTokens.size();
59 Result->VarargsElided = VarargsElided;
62 // Copy the actual unexpanded tokens to immediately after the result ptr.
63 if (!UnexpArgTokens.empty())
64 std::copy(UnexpArgTokens.begin(), UnexpArgTokens.end(),
65 const_cast<Token*>(Result->getUnexpArgument(0)));
70 /// destroy - Destroy and deallocate the memory for this object.
72 void MacroArgs::destroy(Preprocessor &PP) {
73 StringifiedArgs.clear();
75 // Don't clear PreExpArgTokens, just clear the entries. Clearing the entries
76 // would deallocate the element vectors.
77 for (unsigned i = 0, e = PreExpArgTokens.size(); i != e; ++i)
78 PreExpArgTokens[i].clear();
80 // Add this to the preprocessor's free list.
81 ArgCache = PP.MacroArgCache;
82 PP.MacroArgCache = this;
85 /// deallocate - This should only be called by the Preprocessor when managing
87 MacroArgs *MacroArgs::deallocate() {
88 MacroArgs *Next = ArgCache;
90 // Run the dtor to deallocate the vectors.
92 // Release the memory for the object.
99 /// getArgLength - Given a pointer to an expanded or unexpanded argument,
100 /// return the number of tokens, not counting the EOF, that make up the
102 unsigned MacroArgs::getArgLength(const Token *ArgPtr) {
103 unsigned NumArgTokens = 0;
104 for (; ArgPtr->isNot(tok::eof); ++ArgPtr)
110 /// getUnexpArgument - Return the unexpanded tokens for the specified formal.
112 const Token *MacroArgs::getUnexpArgument(unsigned Arg) const {
113 // The unexpanded argument tokens start immediately after the MacroArgs object
115 const Token *Start = (const Token *)(this+1);
116 const Token *Result = Start;
118 for (; Arg; ++Result) {
119 assert(Result < Start+NumUnexpArgTokens && "Invalid arg #");
120 if (Result->is(tok::eof))
123 assert(Result < Start+NumUnexpArgTokens && "Invalid arg #");
128 /// ArgNeedsPreexpansion - If we can prove that the argument won't be affected
129 /// by pre-expansion, return false. Otherwise, conservatively return true.
130 bool MacroArgs::ArgNeedsPreexpansion(const Token *ArgTok,
131 Preprocessor &PP) const {
132 // If there are no identifiers in the argument list, or if the identifiers are
133 // known to not be macros, pre-expansion won't modify it.
134 for (; ArgTok->isNot(tok::eof); ++ArgTok)
135 if (IdentifierInfo *II = ArgTok->getIdentifierInfo()) {
136 if (II->hasMacroDefinition() && PP.getMacroInfo(II)->isEnabled())
137 // Return true even though the macro could be a function-like macro
138 // without a following '(' token.
144 /// getPreExpArgument - Return the pre-expanded form of the specified
146 const std::vector<Token> &
147 MacroArgs::getPreExpArgument(unsigned Arg, const MacroInfo *MI,
149 assert(Arg < MI->getNumArgs() && "Invalid argument number!");
151 // If we have already computed this, return it.
152 if (PreExpArgTokens.size() < MI->getNumArgs())
153 PreExpArgTokens.resize(MI->getNumArgs());
155 std::vector<Token> &Result = PreExpArgTokens[Arg];
156 if (!Result.empty()) return Result;
158 const Token *AT = getUnexpArgument(Arg);
159 unsigned NumToks = getArgLength(AT)+1; // Include the EOF.
161 // Otherwise, we have to pre-expand this argument, populating Result. To do
162 // this, we set up a fake TokenLexer to lex from the unexpanded argument
163 // list. With this installed, we lex expanded tokens until we hit the EOF
164 // token at the end of the unexp list.
165 PP.EnterTokenStream(AT, NumToks, false /*disable expand*/,
166 false /*owns tokens*/);
168 // Lex all of the macro-expanded tokens into Result.
170 Result.push_back(Token());
171 Token &Tok = Result.back();
173 } while (Result.back().isNot(tok::eof));
175 // Pop the token stream off the top of the stack. We know that the internal
176 // pointer inside of it is to the "end" of the token stream, but the stack
177 // will not otherwise be popped until the next token is lexed. The problem is
178 // that the token may be lexed sometime after the vector of tokens itself is
179 // destroyed, which would be badness.
180 PP.RemoveTopOfLexerStack();
185 /// StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of
186 /// tokens into the literal string token that should be produced by the C #
187 /// preprocessor operator. If Charify is true, then it should be turned into
188 /// a character literal for the Microsoft charize (#@) extension.
190 Token MacroArgs::StringifyArgument(const Token *ArgToks,
191 Preprocessor &PP, bool Charify,
192 SourceLocation ExpansionLocStart,
193 SourceLocation ExpansionLocEnd) {
196 Tok.setKind(Charify ? tok::char_constant : tok::string_literal);
198 const Token *ArgTokStart = ArgToks;
200 // Stringify all the tokens.
201 llvm::SmallString<128> Result;
205 for (; ArgToks->isNot(tok::eof); ++ArgToks) {
206 const Token &Tok = *ArgToks;
207 if (!isFirst && (Tok.hasLeadingSpace() || Tok.isAtStartOfLine()))
211 // If this is a string or character constant, escape the token as specified
213 if (Tok.is(tok::string_literal) || // "foo"
214 Tok.is(tok::wide_string_literal) || // L"foo"
215 Tok.is(tok::utf8_string_literal) || // u8"foo"
216 Tok.is(tok::utf16_string_literal) || // u"foo"
217 Tok.is(tok::utf32_string_literal) || // U"foo"
218 Tok.is(tok::char_constant) || // 'x'
219 Tok.is(tok::wide_char_constant) || // L'x'.
220 Tok.is(tok::utf16_char_constant) || // u'x'.
221 Tok.is(tok::utf32_char_constant)) { // U'x'.
222 bool Invalid = false;
223 std::string TokStr = PP.getSpelling(Tok, &Invalid);
225 std::string Str = Lexer::Stringify(TokStr);
226 Result.append(Str.begin(), Str.end());
228 } else if (Tok.is(tok::code_completion)) {
229 PP.CodeCompleteNaturalLanguage();
231 // Otherwise, just append the token. Do some gymnastics to get the token
232 // in place and avoid copies where possible.
233 unsigned CurStrLen = Result.size();
234 Result.resize(CurStrLen+Tok.getLength());
235 const char *BufPtr = &Result[CurStrLen];
236 bool Invalid = false;
237 unsigned ActualTokLen = PP.getSpelling(Tok, BufPtr, &Invalid);
240 // If getSpelling returned a pointer to an already uniqued version of
241 // the string instead of filling in BufPtr, memcpy it onto our string.
242 if (BufPtr != &Result[CurStrLen])
243 memcpy(&Result[CurStrLen], BufPtr, ActualTokLen);
245 // If the token was dirty, the spelling may be shorter than the token.
246 if (ActualTokLen != Tok.getLength())
247 Result.resize(CurStrLen+ActualTokLen);
252 // If the last character of the string is a \, and if it isn't escaped, this
253 // is an invalid string literal, diagnose it as specified in C99.
254 if (Result.back() == '\\') {
255 // Count the number of consequtive \ characters. If even, then they are
256 // just escaped backslashes, otherwise it's an error.
257 unsigned FirstNonSlash = Result.size()-2;
258 // Guaranteed to find the starting " if nothing else.
259 while (Result[FirstNonSlash] == '\\')
261 if ((Result.size()-1-FirstNonSlash) & 1) {
262 // Diagnose errors for things like: #define F(X) #X / F(\)
263 PP.Diag(ArgToks[-1], diag::pp_invalid_string_literal);
264 Result.pop_back(); // remove one of the \'s.
269 // If this is the charify operation and the result is not a legal character
270 // constant, diagnose it.
272 // First step, turn double quotes into single quotes:
274 Result[Result.size()-1] = '\'';
276 // Check for bogus character.
278 if (Result.size() == 3)
279 isBad = Result[1] == '\''; // ''' is not legal. '\' already fixed above.
281 isBad = (Result.size() != 4 || Result[1] != '\\'); // Not '\x'
284 PP.Diag(ArgTokStart[0], diag::err_invalid_character_to_charify);
285 Result = "' '"; // Use something arbitrary, but legal.
289 PP.CreateString(&Result[0], Result.size(), Tok,
290 ExpansionLocStart, ExpansionLocEnd);
294 /// getStringifiedArgument - Compute, cache, and return the specified argument
295 /// that has been 'stringified' as required by the # operator.
296 const Token &MacroArgs::getStringifiedArgument(unsigned ArgNo,
298 SourceLocation ExpansionLocStart,
299 SourceLocation ExpansionLocEnd) {
300 assert(ArgNo < NumUnexpArgTokens && "Invalid argument number!");
301 if (StringifiedArgs.empty()) {
302 StringifiedArgs.resize(getNumArguments());
303 memset((void*)&StringifiedArgs[0], 0,
304 sizeof(StringifiedArgs[0])*getNumArguments());
306 if (StringifiedArgs[ArgNo].isNot(tok::string_literal))
307 StringifiedArgs[ArgNo] = StringifyArgument(getUnexpArgument(ArgNo), PP,
311 return StringifiedArgs[ArgNo];